﻿using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Demo
{
    class FindArrayIndex
    {
        public static void Demo01()
        {
            int[] arr = {111,123,5,665,25};
            Console.WriteLine(string.Join(",",arr));
            Console.WriteLine("请输入一个数:");
            int num = int.Parse(Console.ReadLine());

            int index = Array.IndexOf(arr, num);
            if(index==-1)
            {
                Console.WriteLine("你输入的{0}不存在!",num);
            }
            else
            {
                Console.WriteLine("你输入的数是{0}索引是:{1}",num,index);
            }
        }
    }
}
